Enrollement defintion

The term enrolled or enrollement is used many time in ICH E6 (R2) however this word is never defined in the glossary of GCP or other ICH related to Clinical trial.
is that on purpose to be flexible on the definition of enrollement as per protocol design ?
to which time point or clinical trial process do you define this process ?
enrollement : ICF signature by the patient or legal representative
enrollement : ICF signatue + obtaining Randomistion number or patient number (for randomised or open studies)
enrollement : ICH signature + eligibity crietria checked and verfied

We have find also sometimes defintion of Enrolled versus Included subjects in some trials
We have also the case of 2 ICF : one for the Elgibity criteria + one for Clinical trial so to which refers ICF signature regarding enrollement ?

Any thoughts/feedback on how do you use this term in clinical trials ?

Many sponsors define enrolment of a subject into the trial as the date the potential subject signs the consent form, as without this signature no trial related screening or trial related documentation can be created. When there are 2 consent forms (as in Phase I trials) it would be the trial specific consent form signing that would denote the enrolment into a trial I would think.

Interesting that the EU guidance with the CTR (Q & A document April 2018) defines, “the date of the first visit of the first subject should be the date the first subject or his/her legally designated representative signs his/her first informed consent to participate in activities that are protocol directed interventions”. The phrase “participate in activities” means participate in the trial and so it is not much of a stretch to use a similar definition to define when enrolment of a single subject begins.